Depth Measuring for Ponds and Stormwater Basins

Figure 1. A castable water column depth finder and fishing pole.

Ponds and stormwater basins can be great resources to have on a property, and they can provide great benefits for the surrounding area. Regular ponds can be a nice attractive feature for a home landscape and can provide a place for recreation. Stormwater basins act as a water quality feature in areas such as subdivisions by filtering out any pollutants and protecting nearby streams as a result. There are two types of stormwater basins, wet ponds (retention basins, always have water) and dry basins (detention basins, normally bowl-shaped depressions of grass that hold water for a few days after it rains). In this month’s article in the Conservation Connection, we will dive into a service that we at Warren County SWCD offer to measure the depth of ponds/basins to ensure they have the correct depth needed to function properly. We offer this service to any resident or business owner in Warren County that has a pond or retention basin they would like to check.
Having the correct depth is very important for the health of a pond. Having adequate depth in a pond enables temperatures to be able to reach a stable level, gives enough room for the wildlife in the pond to thrive, and it prevents weeds and algae from taking over a pond. For stormwater retention basins, having enough depth is important because without the designed depth, the storage capacity of the basin might not be enough to contain large rainfalls, and flooding could occur. Here at Warren County SWCD, we can assist with getting an estimate of the depth by providing a free service using a depth finder.

Depth finders are commonly found in the realm of fishing and used by fisherman to get an accurate depth of the water column for fishing purposes. We have found out that we can use a simple depth finder to find the depths of ponds and basins to assess the health of that water feature. We will come out to any pond or stormwater basin per request and use our depth finder to give a good estimate of how deep the pond/basin is. We provide this service because it is important to keep ponds healthy and keep the designed capacity to make sure the pond still has its storage capacity, and there is enough depth for the fish and desired aquatic vegetation. If a pond is too shallow, the sun can reach the bottom of the pond easily, and excessive algae and can fill up a pond very quickly, and this can lead to fish kills and an undesirable look.

We provide this service free of charge to any Warren County resident or business with a pond to determine if it is time for maintenance on the pond. If you are having excessive algae blooms and fish kills in your retention pond, it might be an indicator of a shallow water column. Ohio Department of Natural Resources recommends a pond with a minimum water column depth of 6-8 feet deep to provide a healthy habitat for fish.
It can be costly to dredge a pond of muck that accumulates naturally over time, A rough estimate of when pond maintenance is needed is 10-20 years after completion or from its last dredging. It can easily cost up to $100,000 or more to completely dredge a large pond, so you want to be smart with the right time and amount of dredge work. We are happy to come out and collect some rough estimates of pond depth and health, and provide guidance on how much we recommend dredging out of a pond, and what areas of the pond that needs dredged.  We can also provide some contacts through our Contractors List for pond maintenance and dredging to point you in the right direction.
 
If you have general pond/basin questions or have questions about our depth finder or want to schedule a site visit with us, please give us a call at (513) 695-1337.
 
Article written by Seth Byerly, Urban/Agricultural Technician